Purpose: The present study investigated the effects of high-intensity intermittent training (HIIT) on lower- and upper-body graded exercise and high-intensity intermittent exercise (HIIE, four Wingate bouts) performance, and on physiological and muscle damage markers responses in judo athletes.Methods: Thirty-five subjects were randomly allocated to a control group (n = 8) or to one of the following HIIT groups (n = 9 for each) and tested pre- and post-four weeks (2 training d·wk−1): (1) lower-body cycle-ergometer; (2) upper-body cycle-ergometer; (3) uchi-komi (judo technique entrance). All HIIT were constituted by two blocks of 10 sets of 20 s of all out effort interspersed by 10 s set intervals and 5-min between blocks.Results: For the upper-body group there was an increase in maximal aerobic power in graded upper-body exercise test (12.3%). The lower-body group increased power at onset blood lactate in graded upper-body exercise test (22.1%). The uchi-komi group increased peak power in upper- (16.7%) and lower-body (8.5%), while the lower-body group increased lower-body mean power (14.2%) during the HIIE. There was a decrease in the delta blood lactate for the uchi-komi training group and in the third and fourth bouts for the upper-body training group. Training induced testosterone-cortisol ratio increased in the lower-body HIIE for the lower-body (14.9%) and uchi-komi (61.4%) training groups.Conclusion: Thus, short-duration low-volume HIIT added to regular judo training was able to increase upper-body aerobic power, lower- and upper-body HIIE performance.

Obesity is a risk factor able to trigger several inflammatory alterations and the imbalance between pro- and anti-inflammatory cytokine productions. Physical exercise is an important strategy for reduction of inflammatory established process. The aim of this study was to evaluate the effect of 16 weeks of three exercise training programs in the inflammatory profile and insulin resistance in overweight/obesity. Thirty two men and women (46.4±10.1 years; 162.0±9.1 cm; 82.0±13.6 kg) were divided into three groups for training on a treadmill: continuous at 70% maximum heart rate (HRmax) 5 times a week (CONT); 1×4 min (1-bout) and 4×4 min (high intensity interval training, HIIT) at 90% HRmax 3 times a week. Interleukin (IL) 6 and IL-10, tumor necrosis factor-alpha (TNF-α), insulin and adiponectin levels were analyzed by enzyme-linked immunosorbent assay, and homeostasis model assessment insulin resistance was calculated. After 16 weeks of training blood concentrations of IL-6 decreased in the HIIT group (P=0.035), TNF-α decreased in the CONT (P=0.037) and increased in HIIT (P=0.001) and adiponectin decreased in the three training models. There was a trend towards decreased body weight and body mass index (BMI) after HIIT only (P=0.059 and P=0.060, respectively). Despite the decrease of adiponectin and the increase of TNF-α in HIIT group, insulin sensitivity showed a trend for improvement (P=0.08). HIIT program decreased IL-6 at rest and although not significant was the only who tended to decrease total body weight and BMI. Taken together, our data suggest that both HIIT as well as CONT exercises training program promotes changes in inflammatory profile in overweight/obesity, but dissimilar response is seen in TNF-α levels.

The purpose of this study was to test if different intensities of aerobic exercise could influence abdominal fat, isoforms of BDNF and executive function. Twenty obese men (30.0 ± 5.4 years old; 34.4 ± 3.5 kg/m 2) were randomized to moderate-intensity continuous training (MICT, n = 10) and high-intensity intermittent training (HIIT, n = 10) three times a week for 6 weeks, with isoenergetic energetic expenditure for each exercise session (~ 300 kcal) between conditions. Abdominal fat was assessed pre-and post-intervention; executive function (Coding subtest from BETA-III non-verbal intelligence test and Stroop color and Word test), concentrations of mBDnf and proBDnf were assessed in response to acute exercise pre-and post-intervention. Abdominal fat did not change in either group. There was a significant increase in mBDNF immediately after acute exercise in both groups before and after intervention. proBDNF did not present changes acutely nor after 6 weeks. Executive function presented a main effect of time at pre-and post-intervention time-points Stroop Word and Stroop color and coding subtest presented improved performance from pre-to post-acute exercise session, in both groups. in conclusion, executive function improvements and acute exercise session-induced increases in mBDnf concentration were found from pre-to post-exercise intervention similarly between Mict and Hiit in obese men. There is evidence of an association between augmented abdominal adiposity and lower cognitive function, and it seems that one link between these two parameters is through immunometabolic alterations provoked by proinflammatory cytokines, such as interleukin-6 (IL-6), released from adipose tissue 1-3. Aspects of cognition, such as executive function, which includes working memory, inhibitory control and cognitive flexibility 2, 4, 5 , can be affected by the size of visceral fat 1 and metabolic dysfunction 3, 6 , which are very common conditions in subjects with obesity. In this context, both abdominal fat and cognitive impairments seem to be associated with lower concentrations of brain-derived neurotrophic factor (BDNF) 2, 7 , an important pleiotropic protein directly related to neuron health and brain function 4 .

Metabolic stress is a physiological process that occurs during exercise in response to low energy that leads to metabolite accumulation [lactate, phosphate inorganic (Pi) and ions of hydrogen (H+)] in muscle cells. Traditional exercise protocol (i.e., Resistance training) has an important impact on the increase of metabolite accumulation, which influences hormonal release, hypoxia, reactive oxygen species (ROS) production and cell swelling. Changes in acute exercise routines, such as intensity, volume and rest between sets, are determinants for the magnitude of metabolic stress, furthermore, different types of training, such as low-intensity resistance training plus blood flow restriction and high intensity interval training, could be used to maximize metabolic stress during exercise. Thus, the objective of this review is to describe practical applications that induce metabolic stress and the potential effects of metabolic stress to increase systemic hormonal release, hypoxia, ROS production, cell swelling and muscle adaptations.